Re: Newbie question about db normalization theory: redundant keys OK?

"Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message news:4763dc87$0$5291$9a566e8b_at_news.aliant.net... [snip]

> 6NF:
> R1(a*,b)
> R2(a*,c)
>
> 6NF has at most one non-key attribute.

Thanks for the above definition. It's simple, and easily understood. I actually "invented" this form on my own in my head, but didn't think it was important enough to merit giving it a name.

The interesting thing about 6NF is that the entire argument about NULLS is obviated by 6NF. Instead of including a null, you just omit a row. Then the argument switches to CWA versus OWA. The people who like to argue will always prevail. Sigh.

Are there any INSERT, UPDATE, or DELETE anomalies in DKNF that disappear when one decomposes into 6NF? It has been my understanding that DKNF was final in the sense that no further update anomalies would surface in any DKNF schema.

My understanding comes from my reading in this newgroup. I may have read somebody else's post wrong, or the other poster may have been wrong. When was 6NF invented or discovered? Received on Sat Dec 15 2007 - 08:07:15 CST